ES2459616T3 - Extrusion machine - Google Patents

Abstract

Extrusion machine for continuous machining and / or processing of fluid substances, with at least two parallel (4) rotating shafts in the same direction, which are provided with endless screw segments of transport (11, 13, 15, 24 , 25) and work segments (16, 18, 26, 27, 29, 30) that engage each other and are guided in recesses of the extrusion machine housing, in the form of a circular segment and parallel to the trees (4), in which the work segments (16, 18, 26, 27, 29, 30), which are formed by a screw segment (26, 27) with a gradient greater than the segments of transport screw (11, 13, 15, 24, 25), a recirculating screw segment (18) with opposite gradient direction, a malleable block (16, 29, 30), a blister or a disc Toothed, form with a screw segment endless transport (15, 24, 25) and / or other work segment (30, 29) combined elements of u na single piece (12, 14, 22, 23, 28, 36), and in which the combined element (12, 14, 22, 23, 28, 36) has a length, which is greater than the diameter of the screw without end of transport (D), characterized in that the front surfaces (10, 20) of the combined elements (12, 14, 22, 23, 28, 36) are delimited by circular arcs (AB, EF and AE), which correspond to the diameter of the transport worm (D), the diameter of the transport worm core (d) and at most the axial distance (Ax) of the shafts (4), so that the combined elements (12, 14, 22, 23, 28, 36) are coupled on the trees (4) in such a way that the frontal surfaces (10, 20) delimited by the circular arcs (AB, EF and AE) are aligned with each other.

Description

Extrusion machine

The invention relates to an extrusion machine for continuous machining and / or processing of fluid substances, with at least two rotating shafts in the same direction, which are provided with endless screw segments of transport and work segments that engage between Yes and they are guided in recesses of the extrusion machine housing in the form of a circular segment and parallel to the trees.

Trees equipped with worm segments and work segments can also be arranged in a hollow space in the extrusion machine housing along a circuit with equal centering angles (EP 0 788 867 B1). While the endless screw segments of transport formed by individual elements transport the material to be machined in the extrusion machine from the material feed hole to the material exit hole at the other end of the extrusion machine, the segments of work configured in the same way as individual elements, have a braking and, if necessary, recirculation function. As work elements, for example, malleable blocks can be used, as are known, for example, from EP or 422 272 A1, or the so-called blisters of corresponding diameters, which can also be provided, as it were, as Toothed discs with an outer teeth on the periphery.

Instead of such work elements that compress the material, pressure relief work elements are also used. Thus, for example, an end screw element is known from DE 102 33 213 A1, which has a pressure relief section, neutral in transport, which is formed by an erosion of the comb worm worm screw

Other extrusion machines are known from WO 01/62469 A1 and US 5 672 005 A.

The work elements, which have different surfaces for the different tasks of the procedure, can be combined with each other almost discretionally to optimally take into account the respective general requirement of the procedure technique. The elements of the transport worm and the work elements are juxtaposed hermetically and are connected with a fixed blade against rotation on the support shafts and are actuated, radially and axially positioned exactly, in a coordinated manner by the drive.

The work elements are reduced by virtue of the special requirements of the procedure technique frequently to lengths up to one sixth of the diameter of the worm and are almost always shorter than the diameter of the worm. On the other hand, between the work elements that engage within each other they appear from two adjacent trees a high pressure can appear, in particular when these, such as for example elements of endless screw of recirculation, malleable blocks, blisters or serrated discs , have a diameter that corresponds to the outside diameter of the cuts. In this way, in endless double screw extrusion machines in the area of such work elements forces appear, which lead to a considerable expansion between the trees. These forces also lead in the case of extrusion machines with more trees, in which the trees are arranged along a circle with equal central angles, to considerable wear.

The purpose of the invention is to reduce the average wear in the area of the work elements.

This is achieved through the combination of the features of claim 1.

The work segment, which is connected with a transport screw segment to form a combined single-piece element, can in this case be a recirculation work element with a diameter corresponding to the diameter of the worm, in particular a worm segment with a gradient greater than the transport worm segment or with a gradient direction opposite the transport worm segment or a malleable block, a blister or toothed disc. However, two work segments can also be joined in a one-piece element, for example two malleable blocks of opposite gradient direction or a worm segment with opposite gradient direction or a malleable block.

Through the combination of a transport screw segment and a work segment or two work segments to form a longer combined element, the frictional resistance of the trees is essentially improved in accordance with the invention . At the same time, the expansion forces are distributed over a larger surface, most of the time better lubricated and in this way the surface load is reduced, and therefore the wear and tear. In addition, the combination of several technical requirements of the procedure that can be applied over relatively short length in a segment implies a decisive reduction in the number of pieces, which results in an essential simplification of the equipment and maintenance of the trees as well as of the storage.

To simplify the equipment of the trees, the front surfaces of the combined elements according to the invention are delimited by circular arcs, which correspond to the diameter of the worm core.

of transport and at most axial distance of the trees. The combined elements can then be simply connected to the trees in such a way that the frontal surfaces delimited by the circular arcs are aligned with each other. This essentially facilitates an error-free coupling of the combined elements that mesh with the combined elements of the adjacent trees.

In order to take advantage of the combined elements with respect to the resistance to bending and wear, the combined element has a length of more than the diameter of the worm, in particular more than twice the diameter of the screw endless.

The segment of the transport worm of the combined element is preferably configured with two steps, since a two-step worm leads to a transport amount greater than a three-step worm, but has a screw End of a step a greater resistance to bending.

In the event that the working segment of the combined element has a worm-shaped surface in the same way, that is, for example, a worm segment with a larger gradient or opposite gradient direction, it is configured in the same way with two step preference. In this case, the surface of the working segment can also have only a spiral-shaped development, similar to an endless screw, for example in the case of malleable blocks. Thus, according to the invention, for example, a malleable locking segment can be combined with cam discs arranged in a two-way spiral shape, having a gradient direction corresponding to the endless transport screws , with a two-step malleable block segment with opposite gradient direction to form an element.

At high temperatures, to which the material to be processed in the extrusion machine is exposed, the trees, on the one hand, and the transport and work elements that sit above, on the other hand, expand to a different extent. This results in the formation of an interstitium between the tree and the elements that sit on top of it, in which molten material, for example plastic, can penetrate and, if necessary, it can burn, in any case the tree can be connected with the elements so fixedly that after the cooling of the tree, the elements can only be removed with much difficulty outside the tree.

This problem is still essentially amplified in the combined elements used in accordance with the invention, if necessary to the point that the elements can no longer be extracted, that is, the entire tree must be discarded.

Therefore, according to the invention, preferably each tree is divided into several shorter tree sections, the tree sections being configured so that they can be axially tensioned under tension in the tree core. To facilitate axial tension, preferably at one end of the shaft section in the shaft of the shaft, an axially fixed turning element is provided, which is fixedly provided against rotation with an outer thread, which fits into a internal thread in the core of the adjacent section of the tree. To this end, the section of the tree can have at one end a rotating element with the outer thread and at the other end it can have the inner thread in the core. Sections of the shaft can also be provided, which have such turning elements with external thread at both ends and can be connected with shaft sections, which have corresponding internal threads at both ends in the core.

An axial bore or similar recess is preferably provided in the shaft core of the shaft section, in order to activate the rotating element. To this end, the rotating element may be provided on its side directed towards the axial recess of the tree section with a polygon or a polygonal recess, for example with a hexagonal recess or hexagonal pivot, which are activated by means of a bar, provided at its end with a corresponding opposite polygon, it is inserted into the axial bore of the tree core. Instead of a polygonal recess

or of a polygonal pivot, it is also possible to provide another activation recess or another activation projection in the rotating element which are activated by means of a bar made correspondingly at its end is inserted in the axial bore in the shaft of the shaft.

Each section of the tree with the elements arranged on top fixedly against rotation is fixedly connected against rotation with the adjacent carbol section. For this purpose, between two adjacent sections of the tree a fixed positive connection connection against rotation is provided, for example through a notched or wedged toothed on the outer periphery of the end of the tree core, in which it is housed the rotating element, so that the teeth in the outer periphery collaborate with a notched or wedge teeth in a hub bore at the end of the adjacent shaft section, in which the inner thread is provided, in which it engages the outer thread in the rotating element of the adjacent section of the tree.

The element combined with a work segment and at least one transport screw segment and / or at least one other work segment can be configured in one piece with the tree core of the tree section. However, it is also possible to configure the worm core of the shaft section for the fixed rotation coupling of one or more elements combined.

The combined elements of a single piece according to the invention thus raise the

Bending strength of the trees essentially over a given length, so that the tensile forces that appear on a larger enveloping surface can be better distributed and thus wear is reduced. Furthermore, according to the invention, the number of the components is reduced, which has an advantageous effect on storage as well as on assembly and disassembly. In addition, short work segments can be integrated, for example work segments with a length, which is less than half the diameter of the transport screw, and also those that do not fall within the type grid, for example due to the length construction and / or coupling position. Coupling errors can also be safely reduced in the case of complicated arrangements. The number of airtight places is also drastically reduced and the process space is radially airtight over a certain length of the machine towards a guided tree inside.

The extrusion machine according to the invention is configured at least as a two-shaft extrusion machine. However, it preferably has three or more trees arranged in a hollow space in the housing of the extrusion machine along a circle or circular arc with the same central angle.

The invention is explained in detail below by way of example with the help of the attached drawing. In this:

Figure 1 shows a longitudinal section through a multi-axis extrusion machine.

Figure 2 shows a cross section along line II-II in Figure 1.

Figures 3 and 4 show a side view and a front view of a combined element of transport screws and a work element.

Figures 5 and 6 show a side view and a front view of a combined element according to Figure 1, but with a short working segment and, therefore, with another front wall.

Figures 7 and 8 show a perspective view or front view of a combined element of a malleable block segment with a gradient and a malleable block segment with opposite gradient.

Figure 9 shows a cross section through a two-axis extrusion machine with endless screw segments that engage within each other.

Figure 10 shows a longitudinal section through a tree section with combined element configured in one piece with it.

Figure 11 shows a view of the right end of the tree section according to Figure 10.

Figure 12 shows a view corresponding to Figure 11, but of a tree section with a combined element coupled on the tree core.

Figure 13 shows a cross section along the line XIII-XIII in Figure 11; Y

Figure 14 shows a longitudinal section through a tree of several tree sections with combined elements coupled.

According to Figures 1 and 2, an extrusion machine has a space 2 in a housing 1, which extends along a circle 3. A plurality of trees 4 arranged parallel to the axis around a core are arranged in space 2 5. The housing 1 is closed on the front sides with end plates 6 and 7. The shafts 4 extending through the end plate 6 are driven in the same direction by a gear not shown. The material feed hole is designated 8 and the material exit hole in the end plate 7 is designated 9.

In each shaft 4, several elements 11, 12, 13, 14 are fixedly engaged against rotation by means of a notched teeth. While the elements 11 and 13 are formed by a transport screw segment, the element 12 is constituted by a transport screw segment 15 and a malleable block 16 and the element 14 is constituted by a screw segment. Transport worm 17 with a gradient greater than that of the transport worm elements 11 and 13 as well as a short worm segment 18 with opposite gradient. The malleable block segment 16 and the short worm segment 18 of opposite gradient represent work segments.

On the inner side of the housing 1 and in the core 5, recesses 19 and 20 are provided, respectively, in the form of a circular segment, parallel to the axis and the combined elements 12 and 14 fit with reduced clearance, that is, to a large extent Hermetically At the same time, the endless conveyor elements 11 and 13 and the combined elements 12, 14 greatly engage each other tightly.

Other combined elements 22, 23 of a screw segment are shown in Figures 3 and 4 as well as 5 and 6.

End of transport 24 or 25 and of a working segment 26 and 27, respectively, which are formed by means of a screw segment with a gradient greater than that of the transport endless screw segment 24 and 25, respectively , so that the work segment 27 is set shorter than the work segment

26.

A combined element 28 is represented in FIGS. 7 and 8, which is constituted by a malleable block segment 29 of cam discs which, as indicated through the dashed line 29 ', are arranged with a gradient direction which It corresponds to an endless screw element of transport, and by a malleable block segment 30 of cam disks which, as indicated by the dashed line 30 ', are arranged with opposite gradient direction. That is, in this embodiment, two segments of malleable blocks 29 and 30 are combined as work segments of different function to form an element 28.

As shown in Fig. 99, two combined elements 22 that engage one inside the other have a front surface 10, which are delimited by the arcs of circle A-B, E-F and A-E. The circle arc AB has a diameter, which corresponds to the diameter of the worm D, the circle arc EF has a diameter, which corresponds to the diameter of the core of the worm, and the circle arc AE has a diameter, whose radius corresponds to the axial distance Ax of the two elements 22 combined (see document EP-B-0002131). In the same way, the front surface 10 of the combined elements 22 and 28 according to Figures 3 and 4 or 7 and 8 is configured.

The combined element 23 according to Figures 5 and 6 also has a front surface 20, which is delimited by the arcs of circle AB, B-F 'and AE, but additionally by the arc of circle 32, which corresponds to a semicircle with the diameter of the worm core.

Through the frontal surfaces, formed by these circle arcs, the combined elements essentially simplify the equipment of the trees, since the elements must only be coupled until their frontal surfaces are aligned with each other.

Each tree 4 is divided into several short tree sections, which can be configured differently. Thus, for example, in the tree section 33 according to figures 10 and 11, the tree core 37 and the combined element 36 schematically represented are configured in one piece, while in the tree sections 34, 35 according to Figures 12 and 14 the coupled elements 36 shown schematically are coupled on the core of the shaft 37 in a fixed manner against rotation by means of a wedge teeth.

The sections of the shaft 33, 34, 35 are configured so that they can be tensioned axially under tension in the core of the shaft 37. To this end, a shaft is rotatably housed at one end of each section of the shaft 33, 34, 35 turning element 41 cylindrical. At its end that projects from the axial recess 39, the rotating element 41 is provided with an external thread 42.

For the axial fixing of the rotating element 41, a wire ring 43 is provided that fits, on the one hand, in a circumferential groove 44 in the cylindrical axial recess 39 in the shaft of the shaft 37 and, on the other hand, in a circumferential groove 45 on the outer periphery of the cylindrical turning element 41.

The wire ring 43 is formed, as follows from Figure 13, by coupling through a tangential bore 48 in the core of the shaft 37 from the side a wire between the circumferential grooves 44, 45.

For the connection of the sections of the shaft, as shown in FIG. 10, a coaxial internal thread 49 is provided at the other end of the section of the shaft 33 in the core of the shaft 37, into which the coaxial outer thread 42 of the adjacent section of the shaft 33.

In order to increase the flexural strength, at the end of the section of the shaft 33, in which the rotating element 41 is arranged, the shaft of the shaft 37 protrudes axially, so that the axial pivot formed by the protruding end of the core of the shaft 46 is inserted into an axial recess 47 at the end of the adjacent section of the shaft 33, so that on the inner side of the axial recess 47 the axial recess with the inner thread 49 is provided.

For the activation of the rotating element 41, the shaft of the shaft 37 is provided with a similar axial through hole or recess 51. The rotating element 41 can have, for example, a hexagonal recess 52, in which a hexagon not shown in a bar is coupled, which is inserted through the axial bore 51, to rotate the rotating element 41 and thus screw the outer thread 41 either inside or outside the inner thread 49 of the adjacent section of the tree 33, to connect the adjacent sections of the tree or separate them from each other. Each section of the shaft 33 is fixedly configured against rotation with the adjacent section of the shaft 33. For this purpose, according to figure 11 on the pivot 46 a wedge teeth 53 is provided, which engages in a wedge teeth 50 in the axial recess 47 of the adjacent section of the shaft 33. In the embodiment according to FIG. 12, the wedge teeth 38 used for the elements 36 on the core of the shaft 37 are finally used.

In Fig. 14, the extrusion direction is designated with arrow 54. The direction for the assembly of the shaft from the sections of the shaft 34, 35 corresponds in the same way to the direction of the arrow 54, while the disassembly direction is opposite the arrow 54. It follows that the ends of the sections of the shaft 34, 35, with respect to the extrusion direction 54, are provided, respectively, at the end upstream of the stream with the rotating element 41.

Claims (2)

1.-Extrusion machine for the continuous mechanization and / or processing of fluid substances, with at least two parallel (4) rotating shafts in the same direction, which are provided with endless screw segments of transport (11, 13, 15, 24, 25) and work segments (16, 18, 26, 27, 29, 30) that engage each other 5 and are guided in recesses of the extrusion machine housing, in the form of a segment circular and parallel to the trees (4), in which the work segments (16, 18, 26, 27, 29, 30), which are formed by a worm segment (26, 27) with a greater gradient that the transport screw segments (11, 13, 15, 24, 25), a recirculating screw segment (18) with opposite gradient direction, a malleable block (16, 29, 30), a Blister or a toothed disk, form with a screw segment endless transport (15, 24, 10 25) and / or other work segment (30, 29) elements combines two in one piece (12, 14, 22, 23, 28, 36), and in which the combined element (12, 14, 22, 23, 28, 36) has a length, which is greater than the diameter of the transport screw (D), characterized in that the front surfaces (10, 20) of the combined elements (12, 14, 22, 23, 28, 36) are delimited by circular arcs (AB, EF and AE), which correspond to the diameter of the transport worm (D), the diameter of the transport worm core (d) and maximum axial distance 15 (Ax) of the trees (4), so that the combined elements (12, 14, 22, 23, 28, 36) are coupled on the trees (4) such that the front surfaces (10, 20) delimited by circular arcs (AB, EF and AE) are aligned with each other. 2. Extrusion machine according to claim 1, characterized in that the combined element (14, 22, 23, 28) is configured in two steps.